Project 3 - Abstract Project 3 seeks to determine whether specific modifications to CD4 CAR T cells can enhance their ability to suppress HIV and reduce the latent HIV reservoir. These modifications include protecting CAR T cells from T cell exhaustion and infection, improving the frequency and tissue distribution of these cells, and ultimately exploring whether they can synergize with latency reversing agents (LRA) and CD19 B cell-specific CAR Ts to co-target HIV and B cell cancer. Specifically, we will leverage the expertise of Project 1 (prevent or reverse T cell exhaustion), Core B (preferred CAR integration sites), and Project 4 (CAR T manufacturing platform) to build upon our preliminary data demonstrating the ability of CD4 CAR T cells to suppress HIV in vivo. We will test these concepts in vivo utilizing a humanized mouse model that infuses T cells from well-controlled HIV-infected individuals to accomplish the following goals: Aim 1: Identify approaches to protect CD4 CAR T cells from dysfunction in vivo. AIM 2: Identify approaches to enhance the frequency and tissue distribution CD4 CAR T cells in vivo. Aim 3: Determine the in vivo efficacy of CAR T cells to co-target the HIV reservoir and CD19+ tumors. Therefore, utilizing a humanized mouse model of HIV infection, we hypothesize that enhanced CD4 CAR T cells will be capable of controlling HIV and targeting the HIV reservoir, providing insight into the mechanisms required to achieve a functional HIV cure